Dental plugging instrument.



G. B. SNOW. DENTAL PLUeeTNe INSTRUMENT.

APPLIOATIUN FILED MAY 3. 1909. v

Patented Feb. 8, 1910.

GEORGEB. sNow, or BUFFALO, NEW YORK.'

DENTAL PLUGGING INSTRUMENT.

Specification of Letters Patent.

Patented Feb. 8, 1910.

Application led May 3, 1909. Serial No. 493,762.

To all whom it may concern:

Be it known that I, GEORGE B. SNow, a citizen of the United States, anda resident of the city of Buffalo, in the county of Erie and State ofNew York, have invented certain new and useful Improvements in DentalPlugging instruments, of which the following is a specification,reference being had to the accompanying drawing, in which- Figure 1 is alongitudinal sectional view of the instrument. Fig. 2 is a lateral viewof the same, partly in longitudinal section on a plane' at an angle of90 degrees from that shown in Fig. 1. Fig. 3 is a cross section of theinstrument on the line y-y, Fig. l. Fig. 4 is a cross section of thesame on the line :v -m, Fig. l.

This invention relates to dentists plugging instruments, used forconsolidating the gold or other metals employed for filling cavities inteeth, and more especially to the variety of said instruments known asthe automatic mallet; with which blows are delivered upon the fillingmaterial by pressing the instrument repeatedly against it. Theseinstruments usually contain two springs; a hammer spring, by which ahammer is impelled to deliver the blow, and a thrust spring, by means ofwhich the toolholder is thrust outwardly after a blow has beendelivered, and the parts of the instrument brought into proper relationfor the delivery of another blow. The hammer spring has heretofore beengiven a variable amount of compression for varying the force of theblows delivered by the instrument, while the thrust spring has had aninvariable amount of compression, only sufficient to enable it toperform its office of restoring the parts of the instrument to thepositions necessary for the repetition of the blow.

The object of this invention is the production of an instrument having aXed amount of compression for the hammer spring and a variable amount ofcompression for the thrust spring; the latter being strengthened so thatthe greater part of the consolidation of the filling material will beaccomplished by pressure instead of the concussion of the hammer blows;and the operation of the instrument thus made to simulate the usel ofthe hand plugger and hand mallet.

In the drawing, 1 represents a tubular casing which forms the body ofthe instrument. Threaded into its lower end is the nosepiece 2 whichshoulders against the end of the casing l. The compression cap 3 fillsthe upper end of the casing 1, having a long thread and considerablelongitudinal movementI in said casing. The toolholder 4 having in itslower end a socket 14 for the reception of plugging tools, passesthrough the nosepiece 2 and longitudinally through the casing l; itsupper end sliding in a socket 5 in the compression cap 3. The outwardmovement of the toolholder is arrested by contact of the heel of thetripping device 12 with the inner end of the nosepiece 2, as is plainlyshown in Fig. 2. The abutment plate 6 rests upon a shoulder formed uponthe toolholder 4 and a strong spiral thrust spring 7 is interposedbetween it and the inner end of the compression cap 3. The tubularcasing also contains the hammer 9 which is actuated by the hammer springl0, which is interposed between the hammer 9 and the abutment plate 6.The hammer is released by the tripping device 12-13 in the manner commonto the instruments known as automatic mallets, and then delivers a blowupon the collar l1 which is secured upon the toolholder by the cross pinl5. When the hammer has delivered its blow, its further downwardmovement is arrested by the feather 16, which is securely attached to,and forms a part of, the casing l.

To operate this instrument, a plugging tool is placed in the socket 14of the toolholder 4 and the compression cap 3 is screwed down upon thethrustspring 7, the amount of compression being shown by the scores 8upon the compression cap 3, running up to fifteen pounds or more. Thepoint of the plugging tool being placed upon the tilling material whichis to be consolidated in the tooth cavity, pressure is made upon theinstrument, causing the casing 1 to slide downward over the toolholder 4against the resistance of the thrust spring 7; the tool being thusforcibly pressed against the lilling material to consolidate it.Eventually, the hammer 9 is released by the operation of the trippingdevice 12-13, and the pressure which has been exerted upon the fillingis followed by a blow from the hammer 9. The noise made by the blownotifies the operator to Withdraw the instrument and replace it upon thefilling, When the same process is repeated.

By properly adjusting the relative force of the tivo springs, it ispossible to condense the iilling almost entirely by hand pressureinstead of by the percussive force of the blows, as With the ordinaryautomatic mallet; With the result of doing much less injury to the toothsubstance; something which often occurs When the automatic malletI isused by inexperienced hands.

I claim as my invention,

l. A dental plugging instrument consisting of a tubular casing, atoolholder mounted to be moved longitudinally in said casing, a thrustspring bearing upon said toolholder, a screw cap compressing` the thrustspring, a reciprocating hammer, a spring for actuating said hammer, anda, tripping device 20 to be moved longitudinally in said casing 25 andshouldered to support an abutment plate, a thrust spring interposedbetween said abutment plate and an adjustable compression cap, a hammer,an actuating spring interposed between the hammer and the 30 abutmentplate, and a tripping device for releasing said hammer; substantially asdescribed.

GEORG-E B. SNOV.

Vitnesses JAMES C. Gow, IRVING T. VVHALEN.

